The Australian group calling itself The Galileo Movement uses the “Galileo as rebel” stereotype to lend moral support to their cause, seeing themselves as brave people standing up to the scientific establishment. A keystone of their argument is that carbon dioxide is harmless, and that there is no scientific People do love a rebel, but let’s face it: just because the establishment is sometimes wrong doesn’t mean it is always wrong. Global warming is not a manufactured crisis; the science of how greenhouse gases retain infrared radiation — heat — is very well understood, and I even teach it in my basic astronomy courses. (See also this article in The JAYFK, though be aware of swears.)

In case we need reminding: Galileo used observational evidence to undermine the Earth-centered theory of the universe that was accepted in his day. The geocentric model was as much received wisdom and religious dogma as it was a scientific idea — the primary charge against Galileo was heresy, after all, not being scientifically incorrect. Scientific crackpots use a similar argument: “Einstein’s theories are correct; Einstein’s theories were not accepted by the community at first; my theories are not accepted by the community; therefore, I am correct, just like Einstein!” The Galileo Movement says “Galileo was right; the establishment was wrong; we are opposed to the establishment; therefore, we’re right, just like Galileo!”

Geocentrism fell because the evidence didn’t support it, and today Galileo’s views (with significant additions from Kepler, Newton, and modern astronomy) are the establishment. Years of research have bolstered his position, when it could have been overthrown by subsequent observation; it is establishment because the evidence supports it. Climate science isn’t an easy field, but there is overwhelming consensus that global warming is real and human-caused, based on years of research and enormous quantities of data.

The difference is that if we fail to act on global warming, we won’t just have one scientist sitting under house arrest.